There is publicly known a pressing tool used for fixing a crimp or solderless terminal to a wire cable. In this instance, when a cable diameter or the crimp terminal differs, a tool head (an exchange tool) must be replaced with a counterpart complying with appropriate specifications in some cases. Further, tools that process a target other than the crimp terminal, e.g., a tool used for cutting a wire, cable, a steel wire, and others are widely used, and a tool head (the exchange tool) must be replaced in each of these tools when a diameter of a processing target differs.
Here, although there are many kinds of application pressures, e.g., an application pressure generated by a manual lever or an application pressure based on an air pressure or a hydraulic pressure, a hydraulic type is convenient in order to produce a large pressure. A hydraulic type or a pneumatic type usually requires a hydraulic pump or a pneumatic pump separately from a work tool, and an entire apparatus enlarges. Therefore, there is a driver (an electric hydraulic type) that drives a hydraulic pump with the use of an electric motor provided to a tool itself and actuates a pressing tool by a generated hydraulic pressure.
Since this electric hydraulic type is relatively small and light in weight and can provide a large application pressure based on an oil pressure, it is used for a portable tool. In this case, there is one that has an exchange tool mounted in a bifurcated mounting portion protruding toward a tool main body side and fixes the exchange tool and the mounting portion by using a penetrating locking bolt.
A locking bolt (5) disclosed in Patent Document 1 is constituted of a shank having a circular cross section and a bolt head (13) provided at one end thereof, and a securing recess 10, a longitudinal groove 11 extending in a longitudinal direction of the shank, and a blocking surface 18 that separates the longitudinal groove 11 from the securing recess 10 are formed on the shank. A depth of the securing recess 10 is equal to at least a depth of the longitudinal groove 11.
A securing element captivity is provided to one fork leg 2 of fork legs 2, 3 provided to the tool main body in a bifurcated manner. A securing element 7 held here is held on the securing element captive in a state that it is engaged with one of the longitudinal groove 11 and the securing recess 10 by constant engagement. The locking bolt 5 is movable in a bolt receptacle 4, which is a through hole provided in the fork leg 2, in the range between a lock position and a release position. A compression spring 15 is compressed and disposed between the fork leg 2 and the bolt head and energizes the locking bolt 5 toward the release position.
At the time of the locking the locking bolt 5, the securing element 7 engages with the securing recess 10. The securing recess 10 is formed on a surface of the locking bolt 5. To move the locking bolt 5 to the release position, the securing pin 7 is moved to the longitudinal groove 11. At the time of starting movement of the locking bolt 5, the securing pin 7 fixed in the securing recess 10 is guided by the longitudinal groove 11. Here, an end of the longitudinal groove 11 is terminated at a position away from a free end 12 of the locking bolt 5. As a result, the longitudinal groove 11 forms a stop at an unlock position (the release position) in cooperation with the securing pin 7. Consequently, the locking bolt 5 is held in a receiving neck 1 of the tool (Patent Document 1, Col. 6, Lines 54-67).
According to the invention disclosed in the Patent Document 1 as described above, at the time of releasing the locking bolt 5, the securing pin 7 is brought into contact with and held at the end of the longitudinal groove 11 (an end of the bolt on the free end side), and hence it serves as a retainer of the bolt.
Patent Document 2 is adopted as a prior art in the Patent Document 1. According to the Patent Document 2, a cylindrical security sector 17 energized toward a push-in side is provided at one end of a locking bolt 7, and a bevelled part 29 (a running-up slope) used for moving a locking pin 10 having a semispherical tip from an annular security sector 27 is formed on the cylindrical security sector 17 (see Patent Document 1, Column 1, Lines 33-61, “Background section”). That is, when the security sector 17 is pulled toward a pull side (an opposite side of the push-in side), the beveled part 29 of the security sector 17 pushes the locking pin 10 toward an outer side (a direction to push from the annular sector toward the outside) to effect unlocking, and the lock bolt 7 is released together with the security sector 17.
Here, an annular recessed part 33 is provided at an outer periphery of the other end (a free end side) of the bolt 7, and the locking pin 10 is engageably inserted into this part to serve as a retainer of the bolt. A side surface of the recessed part 33 on the security sector 27 side is formed as a bevelled part 34, and the locking pin 10 automatically moves out of the recessed part 33 at the time of pushing in the bolt 7 for locking. It is described that the invention in Patent Document 1 is configured to simplify handling with respect to Patent Document 2 as the prior art (Patent Document 1, Column 1, Lines 57-61).